But the new rate plans don’t take effect until June 7, so there’s still a wee bit of time for new customers to nab an iPhone or iPad under the current unlimited plan offerings. Considering the expectation of a possible front-facing video camera that’s sure to gobble up data on AT&T’s network, it just might make sense to buy a current iPhone 3GS to gain the unlimited data contract and hope you can return the old model for a new one next week. The newest iPhone hardware is widely expected to launch at Apple’s WWDC event next Monday, the same day the new AT&T tiered pricing plans kick in.